pillwort

from WordNet (r) 3.0 (2006)

pillwort
    n 1: European water fern found around margins of bodies of water
         or in wet acid soil having small globose sporocarps [syn:
         {pillwort}, {Pilularia globulifera}]

from The Collaborative International Dictionary of English v.0.48

Pillwort \Pill"wort`\, n. (Bot.)
   Any plant of the genus {Pilularia}; minute aquatic
   cryptograms, with small pill-shaped fruit; -- sometimes
   called {peppergrass}.
   [1913 Webster]

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